Drafting machine



April 1968 l M. T. WOOLEY 3,376,647

DRAFTING MACHINE Original Filed Sept l7, 1964 5 Sheets-Sheet l INVENTORM. T. WOOLEY A ril 9, 1968 DRAFTING MACHINE 3 Sheets-Sheet OriginalFiled Sept. 17, 1964 FIGB INVENTOR a r April 9, 1968 M. T. WOOLEYDRAFTING MACHINE 3 Sheets-Sheet 3 Original Filed Sept. l7, 1964 FIGIO L'05 INVENTOR United States Patent 3,376,647 DRAFTING MACHINE Marl T.Wooley, 6147% Santa Fe Ave., Huntington Park, Calif. 90255 Continuationof application Ser. No. 397,329, Sept. 17, 1964. This application Apr.10, 1967, Ser. No. 629,830 6 Claims. (Cl. 33-30) ABSTRACT OF THEDISCLOSURE An ellipsograph for guiding a tool or pen through a circularor non-circular path which includes pivotally mounted pendulum arm andhorizontal arm associated at their free ends with a pair of relativelymovable pivot pins operating between the free ends of said pendulum andhorizontal arms with means for adjusting the relative eccentricity ofthe pivot pins whereby a carriage mounted on one of said pivot pins willbe caused to move through a circular or non-circular path depending uponthe relative positions of the pivot pins.

This application is a continuation of application Ser. No. 397,329 filedSept. 17, 1964, now abandoned.

This invention concerns a drafting machine and more particularly aninstrument of geometric nature that provides for the artist anddraftsman a machine that facilitates lay-out, design, and inking detailsby combining both lay-out and inking work into one operation where everpossible.

The instrument of the present invention operates easily, is accurate,versatile, and has a sense of touch. It is hand operated and has beenfound useful in technical illustration, isometric, and perspectivedetail.

This drafting instrument will draw straight lines such as horizontal orvertical lines as well as inclined lines such as radial lines found ondials and obtuse and acute angles found in geometric figures. Themachine will also draw circles with or without centers and ellipses withmajor and minor radii which can be changed or adjusted simply, givinguntold sizes and shapes. These ellipses may also be drawn at any desiredangle. In addition a dial and lettering device makes it possible to drawnumerals and letters around the circumference of a dial with the letterseither upright and vertical to each other or oriented away or toward thecenter of the dial. This same dial and lettering device is very usefulin floral and composite designs.

This instrument will also draw spirals, perspective and isometricconfigurations through simple adjustment to its parts; and in addition,duplication processes such as cross hatching, dial calibrations, patternrepetition etc. is greatly simplified by the inclusion within themachine of devices called repeat devices.

This instrument is adapted to solve many lettering problems found infonts of difiicult nature, and it will draw with pencil and ink and ithas cut clean silk-screen stencils. It is to be understood that thisinvention is not limited in use to employing a scribing or marking toolas its sole source of expression of its movements, but rather that it iscapable of being used with other tools such as machine cutting, dentistdrills, cutting torches and welding electrodes.

This machine performs the drawing work of such drafting instruments asT-square, assorted triangles, compasses and dividers, scales or rules,pencils and ruling pens, irregular curves and protractors. The functionof each above named drafting instrument and others is contained withinthis drafting machine. The advantage of this combination of draftingfunctions is that it speeds up drafting and that the accuraterelationship of the machines metal parts is not subject to change orwear and tear like the more conventional instruments which must bechecked and corrected frequently. Moreover the instrument is ready forinstant use; that is, direct inking without pencil layout for many ofthe simple drafting problems and in addition it is not necessary whendrawing with ink to wait for the ink to dry because the entire machineis above the paper and only the pen touches same, thus savingconsiderable time.

It is, accordingly, an object of the present invention to provide anellipsograph capable of drawing ellipses and having adjustable major andminor axes and which has a minimum of wear and tear and, hence, permitsto draw figures with great accuracy.

A further object of the present invention is to provide an ellipsographof the type disclosed for guiding a tool for marking purposes or fordrawing lines which includes means to rotate the position of an ellipseto be drawn or marked so that the major and minor axes may make anydesired angle with a horizontal line, for example.

A further object of the present invention is to provide an ellipsographof the type disclosed which further includes horizontally and verticallyslidable carriages for drawing horizontal or vertical lines as well aslines at an angle.

In accordance with the present invention an ellipsograph for guiding amarking tool or a pen includes essentially three pivot points. Apendulum arm is pivoted about the first pivot point and has its otherfree end connected to the second pivot point. Means are provided foradjusting the relative positions of the second and third pivot points.This determines the major and minor axes of an ellipse to be marked ordrawn. Hence, when the pendulum arm is rotated about its three pivotpoints a marking tool will describe an ellipse.

In addition means are provided for rotating the position of the secondpivot with respect to that of the third pivot point. This, in turn,permits to rotate the position of the major and minor axes of an ellipsewith respect to a given horizontal line.

Further, it is to be understood that this invention is not to be limitedby the particular drawing shown in terms of construction and arrangementbut rather may employ alterations within the plane of reference of theinvention.

These together with other objects and advantages which will becomeapparent reside in the details of construction and operation as morefully hereinafter described and claimed, reference being had to theaccompanying drawing, forming a part hereof wherein like numerals referto like parts throughout, and in which:

FIG. 1 is an isometric view of the drafting machine;

FIG. 2 is a partial cross-sectional view taken on the line Z-2 of FIG. 1with the elements arranged in the position shown in FIG. 4;

FIG. 3 is a cross sectional view along the line 33 of FIG. 1;

FIG. 4 is a diagrammatic top plan view showing the principles of motioninvolved by the top portion of the ellipse mechanism in forming anellipse;

FIG. 5 is a diagrammatic top plan view showing the principles of motioninvolved by the top portion of the ellipse mechanism but with theeccentric crank at nearly angles to that shown in FIG. 4;

FIG. 6 is a diagrammatic top plan view of the dial and lettering devicediscs showing the principles of motion involved in their use;

FIG, 7 is a cross sectional view of the dial and lettering device alongthe line 44 of FIG. 6 when the discs 73, and 77 are concentric about thecenter 112;

FIG. 8 is a diagrammatic top plan view of the rotary repeat device;

as indicated by and FIG. 9 is a diagrammatic top plan view of the linearrepeat device; and

FIG. 10 is a dial design which indicates the letter orientation about adial and same is used in explanation of the dial and lettering device.

Referring particularly to the drawings, a base member A containing orholding: a fixed cross arm 6 fixed to the base member A on riser blocks5 having on its top surface and on the far edge a rule 7 fixed to same.Cross arm 6 supports cross carriage B which supports horizontal armwhich'in turn supports horizontal carriage C. Coaction of these arms andcarriages with tool carriage and tool provides the means for executionof vertical and horizontal lines.

A perspective device is slidably attached to cross arm 6 by slider 23 onwhose bottom surface is fixed a perspective arm 28. Slider block 26moves over the surface of arm 28 and is fixed where desired by thumblock 24. A short rectangular arm 25 at right angles to the perspectivearm is fixed to slider block 26 and acts to hold and engage and letrotate the radial crank by engaging said crank and arm with a vanishingpoint pin 27 which passes through a hole in end of arm 25 and throughhole 49 in crank 50. The co-action of the perspective device with thecrank 50 is such that if the two are engaged by vanishing point pin 27than the crank 50 is pivotally moveable at said point of engagement andexecution of converging lines is possible.

A dial and lettering device consisting of a protractor disc 73 whichturns in a circular cavity cut into base A and a scribe mark for readingsame protractor disc being scribe line 72 located on edge of cavity. A Tshaped cavity 74 runs from the center of disc 73 to its edge and in thisT cavity 74 slides a T shaped block 107 which is attached by a bolt 106screwed into a tapped hole through its face to its base. The bolt 106 isfixed to disc 75; The disc 75 acts as a lock device, a bearing surfacefor disc 77, and as a protractor. Turning disc 75 counterclockwise turnsbolt 106 and thus fixes block 107 in its T slot. Disc 75 may be set at aspecified radius because block 107 can slide in channel 74. The amountof this linear displacement from center is read from rule 115 using edgeof disc 75 asreading edge. Disc 77 turns freely about bolt head 106 andis fixed by lock 105 attached to edge of disc 75. Its edge has a mark 76for reading protractor disc 75. The co-action of disc 77 and disc 73 andinterrelated disc 75 provides the way wherein disc 77 may be moved andplaced and secured in a position eccentrically or concentrically relatedto the point of rotation 112 of disc 73. This eccentric and concentricrelationship of the points of rotation 106 and 112 of the two discs 73and 77 provides the means wherein letters may be placed upright andvertical around the circumference of a dial FIG. 10 when the two discs73 and 77 are eccentrically related to each other and again provides themeans wherein letters may be oriented toward or away from circle centerand along the axis of the various radii FIG. 10 when the two discs 73and 77 are concentrically related to each other. In the operation ofthis dial and lettering device for upright and vertical characters thework tool is located atthe center 112 of disc 73' and the work isattached to disc 77. The tool may move in a horizontal direction but notat right angles to same. In the execution of upright and verticalcharacters this center point 112 of disc 73 is the circum-. ferencelocation of said characters as provided for by the radial movement ofdisc 75 and related disc 77 The letters are made upright and vertical byrotating each disc 73 and 77 a like amount of distance but in oppositedirections as predetermined. In the execution of letters oriented towardor away from dial center as those shown inside of circle FIG. 10, disc77 is concentrically placed on center of disc 73 and the work tool islocated on the radius desired and the characters are executed facingtoward or away from-circle center as desired. Floral compositesareexecuted this way also.

A cross carriage consisting of: a horizontal arm 30 fixed'on block 20which through its center has hole 19" drilled to fit bearing 101 snugly.Bearing 101 in turn is fixed to plate 16 with bolt 100. An indentedshoulder is cut into bearing 101 at its bottom so that protractor disc'13 is held fixed when bolt is tight. A protruding shoulder on top ofbearing 101 prevents up and down motion of block 20. Thus block 20 andhorizontal arm 30 which are fixed to each other may be rotated 120 whenthumb lock 14 is released. Support bars 10 and 11 of which there are twoto a side are secured to plate 16 with bolts 102 of which there arefour. Bolts 102 also secure and fix bearing wheels 9 of which there arefour between support bars 10 and 11. Four bearing wheels are alsoaifixed inside of support bars 10 and 11, two riding on top of cross arm6 and two beneath. These last two bearing wheels being on the far sideof cross arm 6 and the other two bearing wheels being on the near sideof cross arm 6 FIG. 1. A bolt passes through bolt hole 104 and pro.vides the means wherein bars10 may be drawn together to secure a snugfit of bearing wheels 9 and 103 on cross arm 6.

Thumb lock 12 is used to prevent motion of carriage B. A rule readingblock 8 has a scribe mark on its near end and is used to read rule 7FIG. 1.

On the unsecured end of horizontal arm 30 is located a slider 68 that issecured with thumb 100K169. Attached to slider 68 is a shaft thatprojects to a short cylinder 70 which has a ball bearing 71 in its lowersurface. This slidable support device serves the purpose of keepinghorizontal arm 30 level and true to block 20 and base A and at the sametime permits movement of horizontal.

arm 30 because of ball bearing 31. A rule 48 is fixed on center and onthe top surface of horizontal arm 30: A rule reading block 47 with ascribe mark on its near edge is used to read rule 48.

The pendulum arm 29 has astop slider21 shown in FIG. 1 but this stopslider 21 is only a portion of a total device shown in FIG. 9 whosepurpose is toprovide a 1 device capable of repeating some particularlinear dimension over and over again. This device is called a linearrepeat device.

The linear repeat device consists of two stop sliders 21' (22 or 67) and111, a shaft 109 ties stop slider 21 and 111 I together by projecting orpassing through the hole drilled in the side walls of each slider. Theseholes being equal and opposite each other. Two set screws 110 hold thestop sliders at the particular dimension selected. One stop slider 21sits at the near end of block 17 and the other slider 111 (stop slider)sits at the far end of block 17.

With thumb lock .18 fixing pendulum arm 29 from being pushed or pulledin its retaining channel of block 17 as shown in FIG. 9, the totalrepeat device 111, 109, 21, (108 being loose or open) is pulled from thedotted line position to the solid line position and thumb lock 108 isturned to secure and fix stop slider 21. Thumb lock 18 is then loosenedand pendulum arm 29 is pushed until wall? of slider 21 engages ortouches near end of block (17.

Thumb lock 18 is again tightened and the entire process is repeated.

Speaking generally and group wise with intent toclarify terminology andrelationship of groups of parts to each other: the ellipse mechanismconsists of the horizontal arm 30 which supports a linearly moveablehorizontal carriage C which consists of a bearing housing and avertically attached rotatable crank shaft85 which supports on its topend a radially slidable eccentric crank 33 which is pivotally connectedby a pin bearing 78 to a pendulum arm 29 which is again pivotallyattached by a pivot block 17 and an anchor post 15 to the horizontal arm30 and this combination of parts and their relationship to each otherprovides an adjustable method to control linear movement of thehorizontal carriage C as the crank shaft 85 rotates and also andsimultaneously provides the major radius of an ellipse. The crank shaft85 supports on its bottom end the fixed radial crank which in turnsupports a radially and linearly moveable and adjustable tool carriage Dand tool and their relationship of these parts to each other and tothose attached to the top of crank shaft 85 provides the radius of acircle or the minor radius of an ellipse and an adjustable method ofrelating the effective radial position of the work too] 61 to therotatable crank shaft 85 and also and simultaneously to the effectiveradial position of the pin bearing 78 which together form the effectiveradii of the axes of an ellipse or the radius of a circle through theinteractions of the rotary motion of the work tool 61 with the linearmotion (or lack of same) of the horizontal carriage C.

Speaking specifically and part wise with intent to establishrelationship of parts to each other; an ellipse mechanism consisting of:a bearing housing consisting of a housing plate and support bars 54 and89 of which there are two to a side and which are secured to plate 55with bolts 86 of which there are four. Bolts 86 also secure and fixwheel bearings 53 of which there are four between blocks 54 and 89.Eight wheel bearings 88 are also fastened inside of blocks 54 and 89,two riding on top of horizontal arm 30 and two beneath or four to aside. Thus there are 6 wheel bearings for each side of the bearinghousing, two top, two bottom, and two side bearings. These bearings arefitted snugly about the horizontal arm 30. This fit being furtherenhanced by a threaded bolt which pulls the two support bars 89 evencloser together. The bearing housing provides linear motion parallel tothe horizontal arm 30 and perpendicular to anchor post 15. The linearmotion of this housing is normally perpendicular to that provided by thecross carriage B though not necessarily so because the horizontal arm 30may be rotated through an arc of 120 so that the horizontal carriage Cwould travel at an inclined angle to the cross arm. Part 47 is a rulereading block for scale 48.

A support block 45 is fixed to the near side of bearing housing C. Itsupports the rotary portion of the horizontal carriage C at right anglesto the surface of the work or paper. A hole is drilled the entire lengthof support block 45 so that crank shaft 85 may turn freely in same. Oneach end of support block 45 a circular cavity is cut to hold andreceive the races of thrust bearing 84.

Crank shaft 85 links the curvilinear motion of the components abovesupport block 45 to the components below support block 45. A bolt 87prevents motion of block 51 on the lower end of crank shaft 85, and setscrew 38 prevents motion of the eccentric arm block 36 on the top end ofcrank shaft 85. A round bearing nut 81 the outer surface of which is abearing surface for the eccentric arm block 36, also secures andprevents the plastic disc 42 from any motion except that imparted fromknob 31. A spacing washer 82 provides for the free rotation of repeatarm 37 around its outer edge and at the same time helps to preventmotion of plastic disc 42 by bearing against its bottom surface. Aspacing and retaining nut 83 provides the necessary tension against thethrust bearings 84 and at the same time aids in the support of spacingwashers 82 and bearing nut 81.

An L shaped anchor post 15 is rigidly fixed to far end of horizontal arm30. On center of the top surface of anchor post 15 is a tapped hole toretain bolt 97 which extends through center of ball bearing wheel 98 toattach it to anchor post 15. The outer rm of this ball bearing wheel 98is pressed fit to the bottom and center of pivot block 17 and thus pivotblock 17 may rotate or pivot freely when bolt 97 secures ball bearingwheel 98 to top surface of anchor post 15.

Pivot block 17 has a channel milled on center and lengthwise on its topsurface to fit and hold pendulum arm 29. A thumb lock 18 retainspendulum arm 29 in this slot or channel. Pivot block 17 serves thepurpose of allowing pendulum arm 29 to pivot or rotate and also to slideor move in a linear direction. This linear motion of pendulum arm 29 isnecessary in drawing horizontal lines,

repeat and duplication steps, centering or placement of circles andellipses etc.

A pendulum arm 29 the far end of which is held and retained in a channelcut into top surface of pivot block 17 and the near end is held by pinbearing 78 which extends through bearing hole drilled from top to bottomsurface of pendulum arm 29 to an eccentric crank 33 located on itsbottom surface.

Pin bearing 78 extends through a hole in pendulum arm 29 into a holedrilled on center and into top surface of pin bearing block 113 and isrigidly fixed in the hole by retaining set screw 80. Pendulum arm 29 isrotatably held on pin bearing 78 by retaining cylinder 32 located on topsurface of pendulum arm 29.

A shaft at right angles to pin "bearing 78 connects retaining cylinder32 to knob 31 and thus forms a handle or a rigid extension of eccentriccrank 33 for rotating crank shaft and its related parts. Thus the handle31 and eccentric crank 33 are tied rigidly together by pin bearing 78.

Pin bearing block 113 is fixed on top and center of eccentric crank 33and serves to hold pin bearing 78, set screw 80, and rule reading block34.

An eccentric crank block 36 has a T channel milled on its center and topsurface through which eccentric crank 33 slides. A thumb lock 46 servesto secure and fix eccentric crank 33 in T slot of eccentric crank block36. A hole drilled on center and from top to bottom of eccentric crankblock 36 serves to center same on beaI- ing nut 81. Set screw 38 securesand fixes eccentric crank block 36 to hearing nut 81. The bearing holein bottom of eccentric crank block 36 and a bearing nut 81 and a setscrew 38 allows eccentric crank block 36 to be rotated around crankshaft 85. A rule 35 is fixed to near surface of eccentric crank block36. Eccentric crank block 36 allows eccentric crank 33 to slide in its Tchannel and thus provides a displacement of position of pin bearing 78in relation to the position of crank shaft 85 and pivot block 17.Eccentric crank block 36 also serves the purpose (through being able torotate around crank shaft 85) of alteration of the spacial orientationof the ellipse. Rotation of eccentric crank block 36 changes therelation of eccentric crank 33 to radial crank 50 and likewise altersthe relation of tool 61 to the direction of motion of horizontalcarriage C.

The center points of crank shaft 85 and pivot block 17 are parallel tothe sides of horizontal arm 30.

A tool carriage D consisting of radial crank 50 on whose top surface isfixed a radial crank support block 51. Crank shaft 85 extends into ahole drilled from top to bottom and on center of radial crank supportblock 51 and bolt 87 holds same fixed to each other. A rule 52 is fixedto face of radial crank support block 51 and rule reading block 56 isattached to top surface and near face of tool slider 58. Two ballhearings in holes 57 under spring tension and contained by set screwsare used to take up any slack or slop of tool slider 58. Tool barsupport block 59 is secured to bottom of tool slider 58 by pin bearing93. A hole on center of bottom surface of tool slider 58 and a hole oncenter of top surface of tool bar support block 59 receives this pinbearing '93 which permits raising or lowering tool bar support block 59to properly align inking pen or other tools. The tool slider 58 and toolbar support block 59 are both fixed to pin bearing 93 by the use of setscrews. A rectangular slot is milled into the bottom of tool bar supportblock 59 of such size that tool bar 62 fits the slots sides snugly butmay be raised and lowered sufficient distance to allow all tools toreach the work surface below them. A pin bearing 64 retains and holdsbars 62 in its slot. A hole drilled from top to bottom of tool bar 62and at its far end receives and holds tool 61. A slit cut in tool bar 62from top to bottom intersects pen hole on center and ex tends back adistance from hole to allow thumb lock 60 to tighten respective sides oftool block against tool 61.

A lever 65 is used to raise and lower tool bar 62. The square edgedlower corners of lever 65 engages the shallow slots 66 when pen 61 israised from work surface. The shallow slots are not engaged by thesecorners when pen 61 is lowered and in work position. A spring 63 givesthe necessary tension to pen 61 when in work position.

The function of the tool device is such that it allows the pen 61 orother tool to be placed on a specific radius in relation to center ofcrankshaft 85 through the act of moving tool slider 58 along radialcrank 50 reading chosen radius from rule 52 with rule reading block 56.The tool or pen may then be lowered to the work surface by moving lever65 to a horizontal position as shown in FIG. 1.

Installation and alignment of the tool 61 and tool bar 62 to the worksurface is simplified by co-action between tool bar support block 59 andtool slider 58 which are linked together by pin bearing 93 thus makingit possible to raise, lower, or turn tool bar support block 59 and thusalso tool bar 62.

The position of the three bearing points (pin bearing 78, crank shaft85, and pivot block 17) to each other determines whether the pendulumarm 29 will move when knob 31 is turned: if pin bearing 78 is set oncenter of crankshaft 85, pendulum arm 29 cant move because there is nodisplacement of position of pin bearing 78 in relation to crank shaft 85and pivot block 17; but if. pin bearing 78 is set off center of crankshaft 85, pendulum arm 29 will move as shown in FIGSs. 4 and 5. If knob31 be turned through a complete circle, pendulum arm 29 will swing likea pendulum because its far end is held rotatably fixed in the slot ofpivot block 17 by thumb lock 18 and its near end is subject to thedisplacement provided for by pin bearing 78 as its rotates around crankshaft 85. The width of this pendulum swing is subject to the distancebetween pin bearing 78 and crank shaft 85.

Crank shaft 85 is rotatably held in support block 45 and same is rigidlyfixed to horizontal carriage C and horizontal carriage C is slidablyattached to horizontal arm 30, thus as pin bearing 78 is rotated aroundcrank shaft 85 the pin bearing 78 provides the displacement of positionnecessary to force pendulum arm 29 to move or swing and this constantlychanging position of pendulum arm 29 provides a leverage point for pinbearing 78 to force horizontal carriage C to move in a linear directionas shown in FIGS. 4 and 5. This linear motion of horizontal carriage Creacts with the rotary motion the pen or tool 61 receives from crankshaft 85 to draw or cut an ellipse on the work surface of base member A,providing pen 61 and pin bearing 78 are properly aligned. for same. Thusthe pendulum arm 29, pin bearing 78, and crank shaft 85 defines thelimits of linear travel of horizontal carriage C as the tool 61 isrotated and in so doing also defines the major ellipse axis. The minorellipse axis is defined by the position of tool 61 in relation to thecrank shaft 85.

The spacial orientation of the ellipse (vertical or horizontal) wheneccentric crank 33 is parallel to radial crank 50 is dependent onwhether the tool 61 opposes or complements the direction of motion ofhorizontal carriage C as determined by position of pen 61 in relation tocrank shaft 85 and pin bearing 78: if the pen be placed so that itfollows the direction of linear travel of horizontal carriage C, then ahorizontal ellipse is formed and if it be placed so that it opposes thedirection of linear travel at right angles or 90 to same, then avertical ellipse is formed.

In setting and adjusting the machine for a horizontal ellipse (eccentriccrank 33 being parallel to radial crank 50), the major and minor radiiof the ellipse are placed on opposite sides and in relation to crankshaft center with the adjustable eccentric crank 33 representing themajor axis of the ellipse and the moveable tool carriage and tool 61representing the minor axis of the ellipse. In the ver-:

tical ellipse setup the major and minor radii are on the 8 same side andin relation to the crank shaft center with the moveable tool carriageand tool 61 representing the minor axis and being always farther fromcrank shaft center than the adjustable eccentric crank 33 and pinibearing 78 representing the major axis of the ellipse. In

-rawing a horizontal ellipse with this machine the center i of theellipse is crank shaft center whereas the center of a vertical ellipse(eccentric crank 33 being parallel to crank 50) is a point directlybelow the center of wherever it is located.

In drawing a vertical ellipse with a major axis of 2.00" and a minoraxis of 1.5", compute the difference between the major and minor axis(in this case .50) and divide this last sum in half (in this case .25")and place eccentric crank 33 on this numerical value for major radius,reading same from rule 35 by use of rule reading block 34. Thisnumerical value may be read from the left or the right of the centerpoint of rule 35. Next compute the minor radius by dividing the minoraxis in half (in this case .75) and then adding this value to the valuefound for tl e major radius (in this case .25" plus .75" equals 1.00"and place pen point on this numerical value by reading rule 52 with rulereading block 56 and either to the left or right of center point as wasdone above. Note that the actual value for the minor radius is .75"

2.00 and a minor axis of 1.50" compute the difference between the majorand minor axis (in this case .50") and divide this last sum in half (inthis case .25") and place eccentric crank on this numerical value formajor radius by reading same from rule 35 by use of rule reading block34 and reading from left or right of center point of rule 35. Nextcompute the minor radius by dividing the minor axis in half (in thiscase .75) and place pen point on this numerical value by reading rule 52with rule reading block 56 and place pen on side opposite crank shaftcenter to that where pin bearing 78 was placed.

Slanting ellipses may be drawn with this machine by releasing eccentriccrank block lock 38 and rotating same a specific number of degrees asread from protractor disc 43 and then relocking the same and proceedingin like manner as above. Slanting ellipses result because the pen pointis so placed and the rotary motion so occurs that they oppose thedirection of linear travel of horizontal carriage in a manner as shownby the ellipses that are drawn.

Slanting ellipses may also be drawn with the eccentric crank block 36left in its normal position (its length parallel to horizontal arm 30and also parallel with radial crank 50) and horizontal arm 30 rotated tosome angular degree desired and then locked in place. Use same procedurefor execution of these ellipses as was used for construction of ellipseswherein the length of eccentric crank block 36 was parallel tohorizontal arm 30.

A horizontal line two times the eccentric crank radius setting may bedrawn when the pen 61 is on crank shaft center and eccentric crank 33 isset off-center of crank shaft center.

A vertical line two times the radial dimension setting of the eccentriccrank 33 and pen point 61 is drawn when both eccentric crank 33 and penpoint 61 are on same dimension and same side of crank shaftcenter.

A circle is executed when eccentric crank 33 is set on crank shaftcenter and pen point 61 is set off center of crank shaft center.

Another method of constructing a vertical ellipse consists of rotatingeccentric crank 33 so that it is at right angles to radial crank 50.Locate pen point 61 and construct vertical ellipse using same procedureas that used pin bearing 78 and that it is added to the major radius.25" because .25" is the when the length of eccentric crank block 36 isparallel to horizontal arm 30.

A rotary repeat device consisting of a plastic disc 42 (which acts as asupporting member for rotation of repeat arm 37 around its edge andallows reading a protractor beneath it) which is fixed to crank shaft 85and thus related to crank handle knob 31 and forces imparted to same. Aprotractor disc 43 is free to rotate around crank shaft 85 and is linkedor related to disc 42 through its stop 40 (attached to its top surface)and this stop 40 is placed between repeat arm 37 (lower surface disc 42)and plastic disc stop 41 (under surface of disc 42). Thus if stop 40 issecurely retained by thumb lock 39 (which fixes moveable stop arm 37 toplastic disc 42) between stops 37 and 41 as shown in FIG. 1 and if thumblock 44 (which locks protractor disc 43 to horizontal carriage C) bealso locked, then no rotation is possible if knob 31 be pushed forrotation; if thumb lock 34 is unlocked, complete rotation of crank shaftand parts is possible. If some portion of a circle or ellipse isdesired, then thumb lock 39 is unlocked and the repeat arm 37 is set atthat desired degree, reading same from protractor scale and then thumblock 39 is again locked as is also thumb lock 44; and now it is possible'for disc 42 to turn when knob 31 is pushed and the amount or degreedisc 42 will turn is determined by the distance between stops 37 and 41.Stop 40 permits and prohibits rotation beyond stops 37 and 41 as shownin FIG. 8.

A duplication of a previous crank shaft 85 rotation is provided for whenthumblock 44 is unlocked and disc 43 is rotated until stop 40 engageseither stop 37 or 41 (depending on direction of rotation) when againthumb lock 44 is locked and knob 31 is forced to move and the rotationis again repeated as shown in FIG. 8. A scribe mark 114 is used to readthe protractor disc 43.

This rotary repeat device provides the means of angular measurements andduplications of same and also provides a method of locking crank shaft85 to prevent rotation f same.

A spiral device consisting of spring post 90 fixed to radial crank 50and connected by tension spring 91 to tie post 92 which is fixed toslider block 58 on one side and on the other side and parallel to radialcrank 50 a tie post 92 connected by cable 94 to a stationary shaft 95having on its bottom end two retaining pins 96 pushed into the worksurface. Top of stationary shaft 95 projects into bottom of crank shafttube 85.

The function of the spiral device is such that it allows the pen or toolto be used with a constantly changing radius. This becomes evident whenit is observed that when knob 31 is rotated, shaft 95 remains stationarybecause pins 96 are imbedded in work surface and that when the tooldevice is rotated and is held on one end by a spring fixed to radialcrank 50 and on the other end by a cable tied to stationary shaft 95,then the cable must either wind or unwind from or on shaft 95 and in sodoing move the tool device either backward or forward on radial crank.The shape of the spiral figure executed is dependent upon the diameterof shaft 95 and also depends on whether the cable winds as shown in FIG.2 as a single layer or as an increasingly thicker layer as the thread ona sewing machine bobbin.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

I claim:

1. An ellipsograph for guiding a marking tool or pen, comprising:

(a) a pendulum arm;

(b) a pivot block including a first pivot pin, said pendulum arm havingan end connected to said pivot p (0) a horizontal ar-m secured to saidpivot block;

(d) a first member disposed on said horizontal arm and spaced from saidpivot block and including a second pivot pin, the other end of saidpendulum arm being connected to said second pivot pin;

(e) a second member including a third pivot pin, said first member beingjournalled in and rotatable about said third pivot pin, wherein ahorizontal carriage is movably mounted on said horizontal arm, andwherein said first and second members are secured to and movable withsaid horizontal carriage;

(f) a tool carriage connected to said second member for supporting atool; and

(g) means for adjusting and locking the relative positions of saidsecond and said third pivot pins with respect to each other wherebymovement of said pendulum arm about said three pivot pins will causesaid tool to describe an ellipse when said second and third pivot pinsdo not coincide.

2. An ellipsograph as defined in claim 1 wherein means are provided foradjustably rotating and locking at Will said second member about saidthird pivot pin, thereby to adjust the angular positions of the axes ofthe ellipse described by said tool upon rotation of said pendulum arm.

3. An ellipsograph as defined in claim 2, wherein a crank is secured tosaid second pivot pin to cause movement of said pendulum arm uponrotation thereof.

4. An ellipsograph as defined in claim 2, wherein a vertical carriagemovable in a vertical direction is provide-d, and wherein said pivotblock and horizontal arm are secured to and movable with said verticalcarriage.

5. An ellipsograph as defined in claim 2, wherein a support is providedfor the work to be marked below said ellipsograph, and wherein said toolcarriage is so arranged that the work is marked within the area definedby said ellipsograph.

6. An ellipsograph for guiding a tool or pen, comprismg:

(a) a pendulum arm;

(b) a pivot block including a first pivot pin, said pendulum arm havingan end connected to said pivot P (c) a horizontal arm associated withsaid pivot block;

(d) a first member disposed on said horizontal arm and spaced from saidpivot block, there being a second pivot pin associated with said firstmember and said pendulum arm;

(e) a second member having a third pivot pin associated with it, saidfirst member being swingable about the axis of said third pivot pin;

(f) a tool carriage movable with and about the axis of said third pivotpin for supporting a tool; and

(g) means for adjusting and locking the relative positions of saidsecond and said third pivot pins with respect to each other wherebymovement of said pendulum arm about the axes of said three pivot pinswill cause said tool to move along a line other than circular when saidsecond and third pivot pins do not coincide, there being meansassociated with said horizontal arm whereby said first and secondmembers may move in a horizontal plane when said second and third pivotsare adjusted.

No references cited.

HARRY N. HAROIAN, Primary Examiner.

